Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e518ddb7 authored by Andreas Mohr's avatar Andreas Mohr Committed by Linus Torvalds
Browse files

[PATCH] fs/namei.c: replace multiple current->fs by shortcut variable 



Replace current->fs by fs helper variable to reduce some indirection
overhead and (at least at the moment, before the current_thread_info() %gs
PDA improvement is available) get rid of more costly current references.
Reduces fs/namei.o from 37786 to 37082 Bytes (704 Bytes saved).

[akpm@osdl.org: cleanup]
Signed-off-by: default avatarAndreas Mohr <andi@lisas.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent c16a02d6

fs/namei.c

+47 −39
Original line number Diff line number Diff line
@@ -518,18 +518,20 @@ static int __emul_lookup_dentry(const char *, struct nameidata *); 
static __always_inline int

walk_init_root(const char *name, struct nameidata *nd)

{

	read_lock(&current->fs->lock);

	if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {

		nd->mnt = mntget(current->fs->altrootmnt);

		nd->dentry = dget(current->fs->altroot);

		read_unlock(&current->fs->lock);

	struct fs_struct *fs = current->fs;



	read_lock(&fs->lock);

	if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {

		nd->mnt = mntget(fs->altrootmnt);

		nd->dentry = dget(fs->altroot);

		read_unlock(&fs->lock);

		if (__emul_lookup_dentry(name,nd))

			return 0;

		read_lock(&current->fs->lock);

		read_lock(&fs->lock);

	}

	nd->mnt = mntget(current->fs->rootmnt);

	nd->dentry = dget(current->fs->root);

	read_unlock(&current->fs->lock);

	nd->mnt = mntget(fs->rootmnt);

	nd->dentry = dget(fs->root);

	read_unlock(&fs->lock);

	return 1;

}
@@ -724,17 +726,19 @@ int follow_down(struct vfsmount **mnt, struct dentry **dentry) 


static __always_inline void follow_dotdot(struct nameidata *nd)

{

	struct fs_struct *fs = current->fs;



	while(1) {

		struct vfsmount *parent;

		struct dentry *old = nd->dentry;



                read_lock(&current->fs->lock);

		if (nd->dentry == current->fs->root &&

		    nd->mnt == current->fs->rootmnt) {

                        read_unlock(&current->fs->lock);

                read_lock(&fs->lock);

		if (nd->dentry == fs->root &&

		    nd->mnt == fs->rootmnt) {

                        read_unlock(&fs->lock);

			break;

		}

                read_unlock(&current->fs->lock);

                read_unlock(&fs->lock);

		spin_lock(&dcache_lock);

		if (nd->dentry != nd->mnt->mnt_root) {

			nd->dentry = dget(nd->dentry->d_parent);
@@ -1042,15 +1046,17 @@ static int __emul_lookup_dentry(const char *name, struct nameidata *nd) 
		struct vfsmount *old_mnt = nd->mnt;

		struct qstr last = nd->last;

		int last_type = nd->last_type;

		struct fs_struct *fs = current->fs;



		/*

		 * NAME was not found in alternate root or it's a directory.  Try to find

		 * it in the normal root:

		 * NAME was not found in alternate root or it's a directory.

		 * Try to find it in the normal root:

		 */

		nd->last_type = LAST_ROOT;

		read_lock(&current->fs->lock);

		nd->mnt = mntget(current->fs->rootmnt);

		nd->dentry = dget(current->fs->root);

		read_unlock(&current->fs->lock);

		read_lock(&fs->lock);

		nd->mnt = mntget(fs->rootmnt);

		nd->dentry = dget(fs->root);

		read_unlock(&fs->lock);

		if (path_walk(name, nd) == 0) {

			if (nd->dentry->d_inode) {

				dput(old_dentry);
@@ -1074,6 +1080,7 @@ void set_fs_altroot(void) 
	struct vfsmount *mnt = NULL, *oldmnt;

	struct dentry *dentry = NULL, *olddentry;

	int err;

	struct fs_struct *fs = current->fs;



	if (!emul)

		goto set_it;
@@ -1083,12 +1090,12 @@ void set_fs_altroot(void) 
		dentry = nd.dentry;

	}

set_it:

	write_lock(&current->fs->lock);

	oldmnt = current->fs->altrootmnt;

	olddentry = current->fs->altroot;

	current->fs->altrootmnt = mnt;

	current->fs->altroot = dentry;

	write_unlock(&current->fs->lock);

	write_lock(&fs->lock);

	oldmnt = fs->altrootmnt;

	olddentry = fs->altroot;

	fs->altrootmnt = mnt;

	fs->altroot = dentry;

	write_unlock(&fs->lock);

	if (olddentry) {

		dput(olddentry);

		mntput(oldmnt);
@@ -1102,29 +1109,30 @@ static int fastcall do_path_lookup(int dfd, const char *name, 
	int retval = 0;

	int fput_needed;

	struct file *file;

	struct fs_struct *fs = current->fs;



	nd->last_type = LAST_ROOT; /* if there are only slashes... */

	nd->flags = flags;

	nd->depth = 0;



	if (*name=='/') {

		read_lock(&current->fs->lock);

		if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {

			nd->mnt = mntget(current->fs->altrootmnt);

			nd->dentry = dget(current->fs->altroot);

			read_unlock(&current->fs->lock);

		read_lock(&fs->lock);

		if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {

			nd->mnt = mntget(fs->altrootmnt);

			nd->dentry = dget(fs->altroot);

			read_unlock(&fs->lock);

			if (__emul_lookup_dentry(name,nd))

				goto out; /* found in altroot */

			read_lock(&current->fs->lock);

			read_lock(&fs->lock);

		}

		nd->mnt = mntget(current->fs->rootmnt);

		nd->dentry = dget(current->fs->root);

		read_unlock(&current->fs->lock);

		nd->mnt = mntget(fs->rootmnt);

		nd->dentry = dget(fs->root);

		read_unlock(&fs->lock);

	} else if (dfd == AT_FDCWD) {

		read_lock(&current->fs->lock);

		nd->mnt = mntget(current->fs->pwdmnt);

		nd->dentry = dget(current->fs->pwd);

		read_unlock(&current->fs->lock);

		read_lock(&fs->lock);

		nd->mnt = mntget(fs->pwdmnt);

		nd->dentry = dget(fs->pwd);

		read_unlock(&fs->lock);

	} else {

		struct dentry *dentry;